﻿using System;
using System.Collections.Generic;
//using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Windows.Forms;

namespace KeyEnter
{
    class MouseHook
    {
        private const int WM_MOUSEMOVE = 0x200;
        private const int WM_LBUTTONDOWN = 0x201;
        private const int WM_RBUTTONDOWN = 0x204;
        private const int WM_MBUTTONDOWN = 0x207;
        private const int WM_LBUTTONUP = 0x202;
        private const int WM_RBUTTONUP = 0x205;
        private const int WM_MBUTTONUP = 0x208;
        private const int WM_LBUTTONDBLCLK = 0x203;
        private const int WM_RBUTTONDBLCLK = 0x206;
        private const int WM_MBUTTONDBLCLK = 0x209;

        public event MouseEventHandler OnMouseActivity;

        static int hMouseHook = 0;

        public const int WH_MOUSE_LL = 14;//low level mouse event
        public const int WH_MOUSE = 7;//normal level mouse event

        HookProc MouseHookProcedure;
        [StructLayout(LayoutKind.Sequential)]
        public class POINT
        {
            public int x;
            public int y;
        }

        [StructLayout(LayoutKind.Sequential)]
        public class MouseHookStruct
        {
            public POINT pt;
            public int hWnd;
            public int wHitTestCode;
            public int dwExtraInfo;
        }

        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
        public static extern int SetWindowsHookEx(int idHook, HookProc lpfn, IntPtr hInstance, int threadId);

        [DllImport("kernel32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
        public static extern int GetLastError();

        [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
        private static extern IntPtr GetModuleHandle(string lpModuleName);

        [DllImport("kernel32.dll")]
        private static extern int GetCurrentThreadId();//获取在系统中的线程ID

        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
        public static extern bool UnhookWindowsHookEx(int idHook);

        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
        public static extern int CallNextHookEx(int idHook, int nCode, Int32 wParam, IntPtr lParam);


        public delegate int HookProc(int nCode, Int32 wParam, IntPtr lParam);


        public MouseHook()
        {
        }

        ~MouseHook()
        {
            Stop();
        }

        public void Start()
        {
            if (hMouseHook == 0)
            {
                MouseHookProcedure = new HookProc(MouseHookProc);

                hMouseHook = SetWindowsHookEx(WH_MOUSE_LL, MouseHookProcedure, GetModuleHandle("user32"), 0);//第一个参数是WH_MOUSE_LL,表示捕获所有线程的鼠标消息，同时最后一个参数必须是0
                //hMouseHook = SetWindowsHookEx(WH_MOUSE, MouseHookProcedure, GetModuleHandle("user32"), GetCurrentThreadId());//只捕获当前应用程序（当前线程）的鼠标消息，最后一个参数是当前线程id，使用GetCurrentThreadId()获得，一定不要使用托管线程id（Thread.CurrentThread.ManagedThreadId)。
                if (hMouseHook == 0)
                {
                    int errorCode = GetLastError();
                    Stop();
                }
            }
        }

        public void Stop()
        {
            bool retMouse = true;
            if (hMouseHook != 0)
            {
                retMouse = UnhookWindowsHookEx(hMouseHook);
                hMouseHook = 0;
            }

            if (!(retMouse))
            {
            }
        }

        private int MouseHookProc(int nCode, Int32 wParam, IntPtr lParam)
        {
            //只处理鼠标左键按下的情况
            if ((wParam == WM_LBUTTONDOWN) && (nCode >= 0) && (OnMouseActivity != null))
            {
                MouseButtons button = MouseButtons.None;
                int clickCount = 0;

                switch (wParam)
                {
                    case WM_LBUTTONDOWN:
                        button = MouseButtons.Left;
                        clickCount = 1;
                        break;
                    case WM_LBUTTONUP:
                        button = MouseButtons.Left;
                        clickCount = 1;
                        break;
                    case WM_LBUTTONDBLCLK:
                        button = MouseButtons.Left;
                        clickCount = 2;
                        break;
                    case WM_RBUTTONDOWN:
                        button = MouseButtons.Right;
                        clickCount = 1;
                        break;
                    case WM_RBUTTONUP:
                        button = MouseButtons.Right;
                        clickCount = 1;
                        break;
                    case WM_RBUTTONDBLCLK:
                        button = MouseButtons.Right;
                        clickCount = 2;
                        break;
                }

                MouseHookStruct MyMouseHookStruct = (MouseHookStruct)Marshal.PtrToStructure(lParam, typeof(MouseHookStruct));
                MouseEventArgs e = new MouseEventArgs(button, clickCount, MyMouseHookStruct.pt.x, MyMouseHookStruct.pt.y, 0);
                OnMouseActivity(this, e);
            }
            return CallNextHookEx(hMouseHook, nCode, wParam, lParam);
        }
    }
}
